The overall goals of this K24 application are to provide Emily Oken MD, MPH with protected time to serve as a mentor to junior clinician investigators, and to support new scientific aims that will build upon Dr. Oken's established work on the lifecourse health effects of maternal perinatal health and nutrition. Dr. Oken is an Associate Professor in the Department of Population Medicine at Harvard Medical School, and a Primary Care Physician at the Gretchen and Edward Fish Center for Women's Health at Brigham and Women's Hospital. She leads several large patient-oriented research studies, including an NICHD-funded R01 of over 14,000 11-year-old children previously enrolled in a randomized trial of breastfeeding intervention; an ongoing NIEHS-funded R01 of maternal prenatal fish consumption, mercury exposure, and child development at age 7 years; and a CDC-funded project to develop an electronic medical record-based system to support gestational weight gain counseling and tracking. Dr. Oken has already successfully served as a research mentor to more than a dozen clinicians in training and PhD candidates. This K24 award would come at a critical time in Dr. Oken's career, as she solidifies her independent research trajectory and seeks to increase her availability to mentor junior investigators. The award will also support a new research investigation that builds on Dr. Oken's ongoing NIH supported work in maternal perinatal nutrition and offspring health. Early studies on the life course effects of early life nutrition focused on poor growth and under nutrition. More recently, a variety of research findings provide substantive evidence that prenatal over nutrition, including exposure to excesses of maternal weight, gestational glucose, and weight gain, is associated with overweight in offspring. However, extant human studies are limited in that few have included outcome measures other than weight. The proposed scientific aims will take advantage of existing data from Project Viva, a unique US pre-birth cohort study of which Dr. Oken is the co-Principal Investigator, to determine the extent to which maternal weight, gestational weight gain, and gestational glucose tolerance are each associated with adiposity and established measures of cardio- metabolic risk among children at age 7 years. This project will also identify novel metabolic markers in children's plasma at age 7 years, using comprehensive metabolic profiling (metabolomics), that are associated with maternal prenatal over nutrition and with child adiposity and standard cardio-metabolic risk factors at the same time point.